Interchangeable electric motor for powered garden implements

Abstract

An electric motor sub-assembly with a gear train or drive train and clutch, which replaces a conventional internal combustion engine unit including its conventional clutch. The speed increase or decrease of the gear train is selected so that irrespective of whether an induction or universal electric motor is used, the speed of the clutch substantially replicates the speed of the conventional internal combustion engine clutch. As a consequence, a wide range of implement frames can accept either the internal combustion engine unit or the electric motor sub-assembly to create differently powered implements with a maximum of commonality of parts.

Description

FIELD OF THE INVENTION[0001]The present invention relates to tillers, cultivators, trimmers, brush cutters, hedgers, lawn edgers, or like garden implements which are normally powered by internal combustion engine. Such implements are generally portable are sold in large numbers, and most households with a garden would have at least one of these implements.BACKGROUND ART[0002]Usually, the internal combustion engine is a gasoline engine including a clutch and the entire gasoline engine unit is often manufactured by a different entity from the entity which manufactures the implement.[0003]It is also known to manufacture such implements with an inbuilt electric motor. Such electric motor powered implements do not need a clutch because electric motors start instantaneously and there is no question of idling, the electric motor is simply switched off if no tilling action, trimming action, etc. is required.[0004]However, the sales of electrically powered implements are very much less than ...

AI Technical Summary

Benefits of technology

[0011]In accordance with a first aspect of the present invention there is disclosed a garden implement comprising a tiller, cultivator, trimmer, brush cutter, hedger, lawn edger or the like, said garden implement having a frame and a rotatable member mounted on said frame for rotation relative thereto, an internal combustion engine unit having an output shaft and being mountable on said frame, and an electric motor sub-assembly mountable on said frame; said garden implement normally being powered by said internal combustion engine unit; said electric motor sub-assembly comprising an electric motor having a motor output shaft, a drive train connected with said shaft and including a gear train and a clutch; said gear train being selected to convert the speed of rotation of said electric motor output shaft to the substantially equivalent speed of rotation of said internal combustion engine output shaft; a housing for said sub-assembly; said electric motor, drive train and electric motor shaft being mounted in said housing; and both said housing and said internal combustion engine unit having a corresponding attachment means to permit said electric motor sub-assembly to be connected with said frame in lieu of said internal combustion engine unit, and to permit said internal combustion engine unit to be connected to said frame in lieu of said electric motor sub-assembly. Preferably the housing includes a switch for the electric motor, thereby making the sub-assembly self contained.

Problems solved by technology

However, the sales of electrically powered implements are very much less than the sales of implements having an internal combustion engine.

This is an important factor which results in electric motor powered implements being different models and lacking common parts relative to internal combustion engine powered implements.

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